Variometer



1.8. E. TOWNSEND.

VAFHOMETER.

APPLICATION FILED APR.10,191\8.

Patented May 3, 1921.

3 SHEETS-SHEET l.

J. S. E. TOWNSEND.

VARIOMETER.

APPLICATION FILED APR. l0, |918.

1,87 6,592. Patented May 3, 1921.

3 SHEETS- SHEET 2.

J. S. E. TOWNSEND.

VARIOMETER.'

vAPPLICATION FILED APR. 10y 1913.

1,376,592. Patented May 3, 1921.

3 SHEETS-SHEET 3.

UNITED VARIOMETER.

Specification of Letters Patent.

Patented May 3, 1922i.

Application led April 10, 1918. Serial No. 227,6i.

To all whom 25 may concern Be it known that l, JOHN SEALY EDWARD TowNsENn, a subject of the `King of Great Britain, residing at 20 Merton street, OX- ford, England, have invented a new and useful Improvement in Variometers, of which the following is a specification.

The object of this invention is to provide a variometer with one xed and one movable coil to give two ranges of inductance in simple relation to each other so that when used with a fixed condenser to form a wave meter two ranges of wave lengths are given by the same graduations on one scale. Also the arrangement may be extended so as to obtain an instrument where three ranges of wave lengths are given by the same graduations on one scale.

My invention is illustrated by' the accompanying drawings, in which Figure l is a front view of an instrument constructed in accordance therewith; Fig. 2 is a horizontal section on the line 2-2; Fig. 3 is a rear view of the fixed frame with its winding; Fig. L- is a section of the Xed frame on the line l-ll; Fig. 5 is a view of the movable frame; Fig. G is a section-.thereof on the line 6 6, Fig. 2; and Figs. 7 and 8 are diagrams of the connections.

A is a box in the front of which is an aperture A1 adapted to receive a. dial B mounted on a spindle C j ournaled in a bearing D1 in the front of a stationary frame D. Secured to the inner end of the spindle by a clip El is a frame E the rear of which is supported by a stud C? mounted in the back of the frame D.

In recesses in the frame D are hxed corner pieces D2 of insulating material, and in lscrew threads cut in these is wound a coil F the ends of which are soldered to tags Fl on ebonite pieces D3 screwed to the back of the frame D. The tags are connected, as shown in Fig. 7, by wires F2, F3, to terminals F4, F5, and F 6, which protrude through the front of the box A.

found upon corner pieces F2 Xed to the frame E is a coil G, the self inductanoe of which is equal to that of the coil F. v rlhe ends of this coil are soldered to tags G1 which are connected by wires G2, G3, passing out through holes bored throu h the length ofthe stud C1 to segments 4, G", mounted on the front of the box A.

The inner frame E being smaller than the outer frame D, a coil wound on it would have a smaller inductance than a coil similarly wound on the outer frame. It is of the essence of this invention that these two inductances be equal, and this effect is obtained by winding the turns of the inner coil G more closely than the turns of the outer coil F, or by making the inner coil of a larger number of turns than the outer. Thus with the frames shown the inner coil may contain 6l turns at a distance of ,16th of a centimeter apart, while the outer coil contains 51 turns at a distance of lgth of a centimeter apart.

Pivoted at the center of the segments is an insulating switch handle H carrying two spring brushes H1, H2. As shown in Fig. l, the switch is in a neutral position, but when it is turned clockwise the brush H1 will connect the terminal F4 to the segment G4, and the brush H2 will connect the terminal F8 to the segment G5, and thus the coils F, G, will be in parallel; when, however, the switch is turned anti-clockwise from the neutral position, the brush H1 will connect the terminal F5 to the segment G4 and the brush H2 will connect an idle stud F7 (similar to the terminals F4, F5 and Fe) to the segment Gf and thus the coils F, Gr, will be 1n series.

From theoretical considerations it may be shown that when two coils, the self inductance of which is equal, are thus mounted and are connected in parallel, the divided circuit behaves toward alternating currents of high frequency as a single coil having'an inductance equal to one quarter of the total inductance of the two coils connected in series; that is to say, that in'any position of the frame E the total inductance of the two coilsv F, G, with the switch H in the series position, is four times their inductance with the switch in the parallel position. Or, while the switch is in the parallel position, a range of inductances is obtained by turning the inner frame from one position to a second, and by changing the switch over to the series position another range is obtained of four times those inductances byturning the inner frame again from the first posltion to the second.

This variometer is very suitable for measuring the lengths of lwaves employed in wireless telegraphy, and I can, with the coils F, G, in series, get a range of wave lengths double those with the coils in arallel.

0n the dial B therefore provide one of eecli coil lying substantially in plane poellel to the exis and the sell induction oi seid coils being equal, a switcli adapted to connect the coils in series 'or in parallel, e seele enel en index, one of the latten being rotatable with tlie seconol frame.

7. in e veiometei, the combination oi e fixed ii-eme, two coils having equal self induction, wound upon it, e rotatable frame, two coils, having equal sell induction, wouncl upon tliis sec-ond iieme, the Seli induction of two latter coils connected in series being equal to the self induction oi the two oinez coils connected in series, and e switeleL etleptefl to connect tlie coils all in ori-es oi partly in sei-ies enti peitly in pei'- l el oi" all panel l P3, in erveiiometei?, the combination ci e. iin-eel fname, two coils nei/ing equal self incl ction, wouncl upon it, e seconcl frame rote wit'liin tlie two coils having equal ssii induction, wound upon this seconfl self infiuction l the two letter nectecl seiies being equel to tbc f the two forni-ei coils conin seiie's, e i e switch ecleptecl to t the. coils ell in seiiies oi1 pertly pei'tlv parallel oi ell in pei'- veffiometelS the combination of e eine, two coils having equal ,seli in- 'on, wound upon it, a second iieme siti within the liest and ifoteteble about two coils, having equal eeltD inducwound upon this seconl treme, tlie se -induction of the two letter coils connectefL in series being equal to time sollt in onction oit/tile two former coils connecteol in series enel eecliturn of eeen coil lying situated within tl exis, two colle n ving-equal sell" incluesubstentiellv in e piene peellel Ato the exis,

tion, wound upon this seconcl i'eine, the

self inflection of the two lett C coils conn sei'ies equal to the sell ne two ioime coils connect enel eeen oi coil lying sezies substantially in e, piene peiellel to tbe eine,

o connect ,tbe coils eil seiies end petlv in ii'elleL e seele iotetelole'with e switch adapteP4 sefies t i i i pnieiiei oi eil incisi-i., one ci the le; tne seeonclrame.

e variometer, the combination nnen freine, e second freine within one ist, one ci' the emes being so mounteny the gt is capaci i notation with respect to Lne?, e coil wound. eecli tesine, 1 f1 u -v ncluction oz; seiol. cot sing equel,

`series enc. peitlv the coil wound on innei` freine lier/ine' e larger numbei: of tuns than that' wounoA on the outein frame, means for connecting the coils in series oi in peellel, e scale enel an index, one of the lette? being rotateble with the rotatable iframe.

12. ln e veriometei, the combination oi e fixed fieme, e seconclireme within the first, one' oi" the fiamesbeing so mounted; that it is capable of notation with respect to the other, a coil wound upon each frame, the self induction oit seid coils being equal, the coil wound upon the innein :freine having a larger number ol tuins pei' centimetei than the coil wound upon the outei' treme, means for connectiiik-fT the coils in series or in parallel, e scale and en index, one of the latter beingrotatable with the rotatable frame.

13. i vuriometei' comprising e treme lieving a' coil woundL thereon, e seconcl iieme also having e coil wound thereon, the seltincluction ot said coils being equal, ineens ici connecting saisi coils either in series or parallel, enel means `loi" producing o iele tive movement between seid coils.,

lei-.ln e veriomete, the combination of e iixecl tienne, e, pluelity of coils, bovine; equal seit induction, wound upon seicl freine, e movable freine, e pluelity ci" coils, having equal self induction, wound upon seis?, second freine, the self influen tion of suifl lest-meitionetlv coils ell connected in sei'ies being equal to the self induction of said iistmentioned coils conneetecl in series, enel e switcli edepteol to connect tlie coils all series ci peitlv in parallel oi ell in pei1- ellel. A

l5. t veriometei compicisinge coil, e sen onfl coil, means for connecting seid coils in 4 series oi1 in pei'ellel, seid coils lieving equal self-induction wlieiebjyv the seliincluction oi the two coils con ectecl in series ,will be loue times the sell-inductence oi tlie two coils connected inr peiellel, enfl the responsive weve length of tlie two coils connected. in series will be equal to two times tlie iespon sive weve length oi' the coils connected in peiellel, enel menne tive movement between seid coils when conu nectetl either in oi peiellel to veiy the seli-inductence between tlie minimum.

maximum limits.

lo, variometei, tlie combination oi 11eme, e seeon, emol-lee iinme ictet'ne liest, e coil wouncl upon eecli e sellE induction of eeen coil being;n seme, 'e swite'n efloptefl to connect coils in seiies oi in pe'fellel', e iliiceot needing tetion oi' tile smellei1 iframe eeuses ieletive movement between the seele the pioclucing e, freien en index, ineens wlieiebv the no 17. In a variorneter, the combination of a fixed frame, a second smaller frame rota-Y table within the first, a coil wound upon each frame, the self induction of each coil being the sam, a switch adapted to connect the coils in series or in parallel, a. xed condenser connected to the terminals of the variometer, a direct reading scale with one set of graduations to give the two ranges of wave length in the proportion. 1:2, an index, and means wherebv` the rotation of the smaller frame causes relative movement between the scale and the index.

18. ln a variometer, the combination oit" a fixed traine,LA two coils, each having the same self induction, wound upon it, a sec.

ond smaller frame situated within the first and rotatable about an axis, two coils, each having the saine self induction, wound upon this second frame, the self induction of the two latter coils connected in series being equal to the self induction of the two former coils connected in series and each turn of each coil lying substantially in a' plane parallel to the axis, a switch adapted to connect the coils all in series or partly in series and partly in parallel or all in parallel, a scale,

Laveno?,

" an index and means whereby the rotation of two latter coils connected in series being equal tothe self induction of the two former coils connected in series andl each turn of each coil lying substantially in a plane par* allel to the axis, a switch adapted to connect the coils all in series or partly in series and partly in parallel or all in parallel, a xed condenser' connected to the terminals of the variometer, a sca-le, an index, and nieans whereby the rotation of the smaller frame causes relative movement between the scale and the index.

ln testimony thatll claim the foregoing as my invention` ll have signed'niy naine this 18th day ot' March, i918. 

